type migration: to void: remove unused variables in simple cases IDEA-158196

diff --git a/java/java-impl/src/com/intellij/codeInsight/intention/impl/SplitDeclarationAction.java b/java/java-impl/src/com/intellij/codeInsight/intention/impl/SplitDeclarationAction.java
index 9ea64d81463bfb9aed7bdd094ec6f3f9b2d38993..b418e0a7c54bd09b26b487049bc0d197b0c3b8a7 100644 (file)
--- a/java/java-impl/src/com/intellij/codeInsight/intention/impl/SplitDeclarationAction.java
+++ b/java/java-impl/src/com/intellij/codeInsight/intention/impl/SplitDeclarationAction.java
@@ -110,8 +110,8 @@ public class SplitDeclarationAction extends PsiElementBaseIntentionAction {
     }
   }
 
-  private static void invokeOnDeclarationStatement(PsiDeclarationStatement decl, PsiManager psiManager,
-                                                   Project project) throws IncorrectOperationException {
+  public static PsiAssignmentExpression invokeOnDeclarationStatement(PsiDeclarationStatement decl, PsiManager psiManager,
+                                                                     Project project) throws IncorrectOperationException {
     if (decl.getDeclaredElements().length == 1) {
       PsiLocalVariable var = (PsiLocalVariable)decl.getDeclaredElements()[0];
       var.normalizeDeclaration();
@@ -140,7 +140,7 @@ public class SplitDeclarationAction extends PsiElementBaseIntentionAction {
         }
 
         final PsiElement parent = block.getParent();
-        decl.replace(statement);
+        final PsiAssignmentExpression replaced = (PsiAssignmentExpression)decl.replace(statement);
         if (!(parent instanceof PsiCodeBlock)) {
           final PsiBlockStatement blockStatement =
             (PsiBlockStatement)JavaPsiFacade.getElementFactory(project).createStatementFromText("{}", null);
@@ -152,13 +152,15 @@ public class SplitDeclarationAction extends PsiElementBaseIntentionAction {
         else {
           parent.addBefore(varDeclStatement, block);
         }
+        return replaced;
       }
       else {
-        block.addAfter(statement, decl);
+        return (PsiAssignmentExpression)((PsiExpressionStatement)block.addAfter(statement, decl)).getExpression();
       }
     }
     else {
       ((PsiLocalVariable)decl.getDeclaredElements()[0]).normalizeDeclaration();
     }
+    return null;
   }
 }

diff --git a/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java b/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java
index 578799603aaf25b83a01c6ae04282b526560f96d..36ac3bda19523d20dd74b3064af658b6758a4f96 100644 (file)
--- a/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java
+++ b/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java
@@ -16,15 +16,20 @@
 package com.intellij.refactoring.typeMigration;
 
 import com.intellij.codeInsight.generation.GetterSetterPrototypeProvider;
+import com.intellij.codeInsight.intention.impl.SplitDeclarationAction;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Pair;
 import com.intellij.psi.*;
+import com.intellij.psi.controlFlow.DefUseUtil;
 import com.intellij.psi.impl.PsiSubstitutorImpl;
 import com.intellij.psi.search.GlobalSearchScope;
+import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.util.*;
 import com.intellij.refactoring.typeMigration.usageInfo.TypeMigrationUsageInfo;
+import com.intellij.util.CommonProcessors;
+import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.containers.HashMap;
 import org.jetbrains.annotations.NotNull;
 
@@ -85,7 +90,13 @@ class TypeMigrationStatementProcessor extends JavaRecursiveElementVisitor {
         break;
 
       case TypeInfection.RIGHT_INFECTED:
-        myLabeler.migrateExpressionType(lExpression, rtype, myStatement, TypeConversionUtil.isAssignable(ltype, rtype), false);
+        if (lExpression instanceof PsiReferenceExpression &&
+            ((PsiReferenceExpression)lExpression).resolve() instanceof PsiLocalVariable &&
+            !canBeVariableType(rtype)) {
+          tryToRemoveLocalVariableAssignment((PsiLocalVariable)((PsiReferenceExpression)lExpression).resolve(), rExpression, rtype);
+        } else {
+          myLabeler.migrateExpressionType(lExpression, rtype, myStatement, TypeConversionUtil.isAssignable(ltype, rtype), false);
+        }
         break;
 
       case TypeInfection.BOTH_INFECTED:
@@ -515,14 +526,27 @@ class TypeMigrationStatementProcessor extends JavaRecursiveElementVisitor {
 
       case TypeInfection.RIGHT_INFECTED:
         PsiType psiType = migrationType != null ? migrationType : right.getType();
-        if (psiType != null && declarationType != null && 
-            !myLabeler.addMigrationRoot(variable, psiType, myStatement, TypeConversionUtil.isAssignable(declarationType, psiType), true) && 
-            !TypeConversionUtil.isAssignable(left.getType(), psiType)) {
-          PsiType initialType = left.getType();
-          if (initialType instanceof PsiEllipsisType) {
-            initialType = ((PsiEllipsisType)initialType).getComponentType();
+        if (psiType != null) {
+          if (canBeVariableType(psiType)) {
+            if (declarationType != null &&
+                !myLabeler.addMigrationRoot(variable, psiType, myStatement, TypeConversionUtil.isAssignable(declarationType, psiType), true) &&
+                !TypeConversionUtil.isAssignable(left.getType(), psiType)) {
+              PsiType initialType = left.getType();
+              if (initialType instanceof PsiEllipsisType) {
+                initialType = ((PsiEllipsisType)initialType).getComponentType();
+              }
+              myLabeler.convertExpression(value, psiType, initialType, isCovariantPosition);
+            }
+          }
+          else {
+            if (variable instanceof PsiLocalVariable) {
+              final PsiDeclarationStatement decl = PsiTreeUtil.getParentOfType(variable, PsiDeclarationStatement.class);
+              if (decl != null && decl.getDeclaredElements().length == 1) {
+                tryToRemoveLocalVariableAssignment((PsiLocalVariable)variable, value, psiType);
+              }
+              break;
+            }
           }
-          myLabeler.convertExpression(value, psiType, initialType, isCovariantPosition);
         }
         break;
 
@@ -535,6 +559,44 @@ class TypeMigrationStatementProcessor extends JavaRecursiveElementVisitor {
     }
   }
 
+  private void tryToRemoveLocalVariableAssignment(@NotNull PsiLocalVariable variable, @NotNull PsiExpression valueExpression, @NotNull PsiType migrationType) {
+    final PsiCodeBlock codeBlock = PsiTreeUtil.getParentOfType(variable, PsiCodeBlock.class);
+    final PsiElement[] refs = DefUseUtil.getRefs(codeBlock, variable, valueExpression);
+    if (refs.length == 0) {
+      myLabeler.setConversionMapping(valueExpression, new TypeConversionDescriptorBase() {
+        @Override
+        public PsiExpression replace(PsiExpression expression, @NotNull TypeEvaluator evaluator) throws IncorrectOperationException {
+          final PsiElement parent = expression.getParent();
+          if (parent instanceof PsiLocalVariable) {
+            final PsiLocalVariable var = (PsiLocalVariable)parent;
+            final PsiDeclarationStatement decl = PsiTreeUtil.getParentOfType(var, PsiDeclarationStatement.class);
+            if (decl == null) return null;
+            final Project project = var.getProject();
+            final PsiAssignmentExpression assignment =
+              SplitDeclarationAction.invokeOnDeclarationStatement(decl, PsiManager.getInstance(project), project);
+            final PsiExpression rExpression = assignment.getRExpression();
+            if (rExpression == null) return null;
+            assignment.replace(rExpression);
+            if (ReferencesSearch.search(var, var.getUseScope()).forEach(new CommonProcessors.FindFirstProcessor<>())) {
+              var.delete();
+            }
+          }
+          else if (parent instanceof PsiAssignmentExpression) {
+            final PsiExpression rExpression = ((PsiAssignmentExpression)parent).getRExpression();
+            return rExpression == null ? null : (PsiExpression)parent.replace(rExpression);
+          }
+          return null;
+        }
+      });
+    } else {
+      myLabeler.markFailedConversion(Pair.pair(null, migrationType), valueExpression);
+    }
+  }
+
+  private static boolean canBeVariableType(@NotNull PsiType type) {
+    return !type.getDeepComponentType().equals(PsiType.VOID);
+  }
+
   private static PsiType adjustMigrationTypeIfGenericArrayCreation(PsiType migrationType, PsiExpression expression) {
     if (expression instanceof PsiNewExpression) {
       if (migrationType instanceof PsiArrayType) {

diff --git a/java/typeMigration/test/com/intellij/refactoring/TypeMigrationTest.java b/java/typeMigration/test/com/intellij/refactoring/TypeMigrationTest.java
index cb1c3191343370ed983823ed764c989718a5aa66..ad7548e1e444c9a19eccaa42ce7e502230afed33 100644 (file)
--- a/java/typeMigration/test/com/intellij/refactoring/TypeMigrationTest.java
+++ b/java/typeMigration/test/com/intellij/refactoring/TypeMigrationTest.java
@@ -846,6 +846,22 @@ public class TypeMigrationTest extends TypeMigrationTestBase {
     doTestFieldsType("Test", myFactory.createTypeFromText(CommonClassNames.JAVA_LANG_OBJECT, null), "a", "b");
   }
 
+  public void testVoidMigrationInVarDecl() {
+    doTestMethodType("migrationMethod", PsiType.VOID);
+  }
+
+  public void testVoidMigrationInVarDeclFailed() {
+    doTestMethodType("migrationMethod", PsiType.VOID);
+  }
+
+  public void testVoidMigrationInAssignment() {
+    doTestMethodType("migrationMethod", PsiType.VOID);
+  }
+
+  public void testVoidMigrationInAssignmentFailed() {
+    doTestMethodType("migrationMethod", PsiType.VOID);
+  }
+
   private void doTestReturnType(final String methodName, final String migrationType) {
     start(new RulesProvider() {
       @Override

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/after/Test.items b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/after/Test.items
new file mode 100644 (file)
index 0000000..b00e81e
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/after/Test.items
@@ -0,0 +1,10 @@
+Types:
+PsiMethod:migrationMethod : void
+PsiMethodCallExpression:migrationMethod() : void
+
+Conversions:
+"" -> $
+migrationMethod() -> $
+
+New expression type changes:
+Fails:

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/after/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/after/test.java
new file mode 100644 (file)
index 0000000..0bc3bea
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/after/test.java
@@ -0,0 +1,11 @@
+class Test {
+
+  static void migrationMethod() {
+  }
+
+  void m() {
+    String sss;
+    migrationMethod();
+    sss = "";
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/before/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/before/test.java
new file mode 100644 (file)
index 0000000..daa00c0
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignment/before/test.java
@@ -0,0 +1,12 @@
+class Test {
+
+  static String migrationMethod() {
+    return "";
+  }
+
+  void m() {
+    String sss;
+    sss = migrationMethod();
+    sss = "";
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/after/Test.items b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/after/Test.items
new file mode 100644 (file)
index 0000000..aa24a2d
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/after/Test.items
@@ -0,0 +1,10 @@
+Types:
+PsiMethod:migrationMethod : void
+PsiMethodCallExpression:migrationMethod() : void
+
+Conversions:
+"" -> $
+
+New expression type changes:
+Fails:
+migrationMethod()->void

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/after/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/after/test.java
new file mode 100644 (file)
index 0000000..54100fb
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/after/test.java
@@ -0,0 +1,12 @@
+class Test {
+
+  static void migrationMethod() {
+  }
+
+  void m() {
+    String sss;
+    sss = migrationMethod();
+    System.out.println(sss);
+    sss = "";
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/before/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/before/test.java
new file mode 100644 (file)
index 0000000..c0c3798
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInAssignmentFailed/before/test.java
@@ -0,0 +1,13 @@
+class Test {
+
+  static String migrationMethod() {
+    return "";
+  }
+
+  void m() {
+    String sss;
+    sss = migrationMethod();
+    System.out.println(sss);
+    sss = "";
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/after/Test.items b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/after/Test.items
new file mode 100644 (file)
index 0000000..b00e81e
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/after/Test.items
@@ -0,0 +1,10 @@
+Types:
+PsiMethod:migrationMethod : void
+PsiMethodCallExpression:migrationMethod() : void
+
+Conversions:
+"" -> $
+migrationMethod() -> $
+
+New expression type changes:
+Fails:

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/after/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/after/test.java
new file mode 100644 (file)
index 0000000..d85fea5
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/after/test.java
@@ -0,0 +1,12 @@
+class Test {
+
+  static void migrationMethod() {
+  }
+
+  void m() {
+    String sss;
+      migrationMethod();
+      sss = "";
+    System.out.println(sss);
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/before/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/before/test.java
new file mode 100644 (file)
index 0000000..8a92d5b
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDecl/before/test.java
@@ -0,0 +1,12 @@
+class Test {
+
+  static String migrationMethod() {
+    return "";
+  }
+
+  void m() {
+    String sss = migrationMethod();
+    sss = "";
+    System.out.println(sss);
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/after/Test.items b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/after/Test.items
new file mode 100644 (file)
index 0000000..aa24a2d
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/after/Test.items
@@ -0,0 +1,10 @@
+Types:
+PsiMethod:migrationMethod : void
+PsiMethodCallExpression:migrationMethod() : void
+
+Conversions:
+"" -> $
+
+New expression type changes:
+Fails:
+migrationMethod()->void

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/after/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/after/test.java
new file mode 100644 (file)
index 0000000..749d889
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/after/test.java
@@ -0,0 +1,10 @@
+class Test {
+
+  static void migrationMethod() {
+  }
+
+  void m() {
+    String sss = migrationMethod();
+    System.out.println(sss);
+  }
+}
\ No newline at end of file

diff --git a/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/before/test.java b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/before/test.java
new file mode 100644 (file)
index 0000000..2396575
--- /dev/null
+++ b/java/typeMigration/testData/refactoring/typeMigration/voidMigrationInVarDeclFailed/before/test.java
@@ -0,0 +1,11 @@
+class Test {
+
+  static String migrationMethod() {
+    return "";
+  }
+
+  void m() {
+    String sss = migrationMethod();
+    System.out.println(sss);
+  }
+}
\ No newline at end of file